Knees still get sore for normal reasons, though, like tight hips, stiff ankles, too much sitting or a big spike in training. Place your feet on the wall, knees bent. Let knees fall outward into a wide diamond shape; soles of feet can touch lightly. Beginner modification: Keep the feet farther down the wall (less hip opening) and use more support under thighs. Beginner modification: Do “mini-bridges”: lift hips just an inch or two, focusing on smooth control.